Real Wool or Not?

About this learning series

Parashath Noah, Laws of Ziziyoth, Page 13: 

2. {Not all fabrics which are commonly thought of as 'wool' are defined as such in Halachah.}  For example, kerman and cashmere are actually goats'-hair, and the Halachah does not regard the material woven from them as wool: a tallith of any of these sorts of material belongs to the second category discussed above in 1.

A G-d-fearing person should be careful to establish that the tallith that he is buying is really of sheeps'-wool, as sometimes goats'-hair, or even camel-hair, is passed off as wool.  It becomes even more difficult to identify what sort of material it is if the warp or the weft is actually of genuine wool, and the rest is of some other sort of material.  A tallith of this sort belongs to the third category discussed above (1), and problems are raised as to what sort of ziziyoth are to be used on it.

This learning should be in memory of Maran, HaRav HaGaon Ovadia Yosef, ztz'l.